CARVER -- Four hours after Neil Entwistle's arrest yesterday, a woman opened her front door a few houses down from the family home of Rachel Entwistle and snapped in anger when asked her reaction to the news.

''I hope they fry" him, said the woman, who identified herself only as Terri. ''They should really take care of him."

But in England, where Entwistle was arrested just before noon in London, the news that he had been charged in the killing of his wife and daughter unnerved former classmates at the University of York. ''I'm utterly, utterly gobsmacked by the whole thing," Owen Rodd, who was president of the university rowing club where Neil and Rachel Entwistle met as students, said by phone.

''As far as we knew, he was a decent guy," said Rodd, who lamented news reports that he believes have been ''overly presumptuous" of Entwistle's guilt.

For nearly three weeks, residents from quiet Carver to bustling London have closely followed the pursuit of the killer of Rachel Entwistle, 27, and Lillian, 9 months old. As the news of the arrest was absorbed yesterday, emotions seemed to pour out, some of bitterness, some of disbelief, and some of deep sorrow.

''Rachel and Lilly loved Neil very much," lawyer Joseph Flaherty said in Cambridge, speaking for a family who had not publicly uttered Neil's name since the slayings. ''Neil was a trusted husband and father, and it is incomprehensible how that love and trust was betrayed in the ultimate act of violence."

In Hopkinton, where mother and daughter were discovered fatally shot Jan. 22 in Neil and Rachel's bed, the town seemed to exhale. ''It's a relief to have this part of the investigation behind us," Police Chief Thomas Irvin said. ''There's still work to be done, but having the person we believe to be responsible in custody is a relief for us and, I believe, a relief for the community."

Outside the five-bedroom Colonial-style house where the Entwistles lived for only 10 days, the cul-de-sac of Cubs Path was swarming with local and British reporters. ''I'm glad it's over," said Diane Norby, who lives near the house. ''I'm glad they've got what they need to make an arrest."

Eric Sonnett, chairman of Hopkinton's Board of Selectmen, said he breathed an ''enormous sigh of relief" when Irvin called him yesterday morning to tell him the news of the arrest. ''I said, 'How are we doing today, Tom?' and he said, 'Better than we have been,' " Sonnett recalled.

''Something very bad happened to two citizens of our town," Sonnett said. ''The fact that we now have an opportunity to know what happened and have a sense of closure, that's a huge relief."

The arrest followed days of speculation on both sides of the Atlantic and tabloid speculation about Entwistle's seemingly idyllic relationship with his wife and daughter. On Feb. 1, when 500 mourners packed St. Peter's church in Plymouth for the funeral for Rachel and her daughter, not a word was spoken about Neil.

''We are heartbroken and at a loss to understand how this happened," Flaherty said on behalf of Priscilla and Joseph Matterazzo, Rachel's mother and stepfather. ''But as our pastor . . . reminded us just eight days ago, 'God didn't do this,' and 'there is evil among us.' "

At the Matterazzo home in Carver, a man who identified himself as Rachel's stepbrother quietly declined comment about the arrest. ''We just found out," the man said.

At a South Carver convenience store, owner Dennis Steliga said everyone was talking about the tragic event. ''What's there to say?" Steliga said. ''I thought he was pretty guilty all along. It was just a matter of time before authorities over there . . . arrested him."

Flaherty, a 30-year friend of the family, said the arrest is not an antidote for the suffering of the many people who loved Rachel Entwistle and her daughter. ''I don't know if it really helps in a situation like this," he said. ''There's never really closure in a matter like this."

Rachel Entwistle ''was the essence of a loving mother, of a loving daughter and a sister," he said. ''She was very close to her family. Everyone that became a friend of Rachel's became a very close friend, and everyone that had any contact with her loved her as a sister."